1. Field of the Invention
The present invention relates to a vehicular running control apparatus for use in, for example, preceding vehicle follow-up running control equipment or the like mounted on a host vehicle running behind a preceding vehicle thereof while maintaining a proper inter-vehicle distance between the host vehicle and the preceding vehicle.
2. Description of the Related Art
There have been proposed vehicular running control apparatuses, each of which sets a target inter-vehicle distance in accordance with a running speed of a host vehicle, detects an inter-vehicle distance between the host vehicle and a preceding vehicle thereof, and controls braking/driving force so that the detected inter-vehicle distance coincides with the target inter-vehicle distance, thus controlling a running state of the host vehicle. Among the vehicular running control apparatuses, the one described in the gazette of Japanese Patent Application Laid-Open No. Hei 11 (1999)-268558 calculates a running speed command value of the host vehicle for allowing the inter-vehicle distance to follow the target value by feedback control for the inter-vehicle distance and a relative speed therebetween, calculates a drive shaft torque command value for following the running speed command value of the host vehicle, and calculates manipulated variables of engine torque and a brake actuator, that is, controlled variables of the driving force and the braking force, for following the drive shaft torque command value, thus controlling the braking/driving force in response to the calculated controlled variables.
It is an object of the present invention to provide a vehicular running control apparatus, which detects an acceleration of a preceding vehicle, and in response to a running state, adjusts a gain by which the acceleration is multiplied, adjusts a deadband width, or adjusts responsiveness of a low-pass filter, thus can obtain a specified response for an inter-vehicle distance.
To achieve the object described above, the present invention provides a vehicular running control apparatus, comprising:
an inter-vehicle distance detection device configured to detect an inter-vehicle distance between a host vehicle and a preceding vehicle;
a host vehicle running speed detection device configured to detect a host vehicle running speed;
a target inter-vehicle distance setting device configured to set a target inter-vehicle distance between the host vehicle and the preceding vehicle based on the inter-vehicle distance detected by the inter-vehicle distance detection device and the host vehicle running speed detected by the host vehicle running speed detection device;
a host vehicle running speed command value calculation device configured to calculate a running speed command value of the host vehicle based on the inter-vehicle distance detected by the inter-vehicle distance detection device, the host vehicle running speed detected by the host vehicle running speed detection device and the target inter-vehicle distance set by the target inter-vehicle distance setting device;
a preceding vehicle acceleration detection device configured to detect an acceleration of the preceding vehicle;
a host vehicle running speed command value correction device configured to multiply the acceleration of the preceding vehicle, the acceleration being detected by the preceding vehicle acceleration detection device, by a specified gain to calculate a host vehicle running speed command value correction amount, and to add the host vehicle running speed command value correction amount to the host vehicle running speed command value to calculate a corrected host vehicle running speed command value; and
a host vehicle running speed control device configured to control the host vehicle running speed based on the corrected host vehicle running speed command value corrected by the host vehicle running speed command value correction device,
wherein a response time constant when the host vehicle running speed control device controls the host vehicle running speed based on the corrected host vehicle running speed command value is set at the specified gain multiplied with the acceleration of the preceding vehicle.